# Sudoku vs Stack by Stack!

The clearest difference is in-app purchases: Stack by Stack! at none against Sudoku's 5. Stack by Stack! also leads on update cadence (every 4 days vs every 5 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Sudoku sells 5 one-off in-app purchases. Stack by Stack! asks for nothing beyond the download.

Sudoku ships an update every 5 weeks, Stack by Stack! every 4 days. The most recent releases landed on August 22, 2026 and September 27, 2026 respectively.

## The numbers

| Metric | Sudoku | Stack by Stack! |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.3 (26 ratings)](https://appshunter.io/ios/app/sudoku-brain-number-puzzle/id6550909667/reviews)** | — |
| Number of ratings | **26** | — |
| Positive reviews | 20.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | Yes |
| Update frequency | Every 5 weeks | **Every 4 days** |
| Monetization | Free with in-app purchases | — |
| Size | 165 MB | 94 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Craox Technologies LLP.](https://appshunter.io/developer/1473554375) | [ByeongUk Choi](https://appshunter.io/developer/1872002178) |

## What reviewers say

### Sudoku

[App page](https://appshunter.io/ios/app/sudoku-brain-number-puzzle/id6550909667)

Engage your mind with a vast collection of classic Sudoku puzzles. This app offers various difficulty levels, helpful tools, and daily challenges to keep you entertained and sharpen your cognitive skills. Enjoy a relaxing yet stimulating experience anytime, anywhere.

**Highlights:** Thousands of Sudoku puzzles, Multiple difficulty levels, Hints and auto-check tools, Daily challenges, Progress tracking, Dark themes, Mistake checker

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Deal - Limited Period | $1.99 | one-time |
| 10 Hints | $1.99 | one-time |
| Remove Ads | $2.99 | one-time |
| 50 Hints | $3.99 | one-time |
| 250 Hints | $14.99 | one-time |


### Stack by Stack!

[App page](https://appshunter.io/ios/app/stack-by-stack/id6760553499)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Sudoku free?

Sudoku is free to download, with in-app purchases available.

### Is Stack by Stack! free?

Stack by Stack! is free to download, with no in-app purchases.

### Do Sudoku or Stack by Stack! have ads?

Both Sudoku and Stack by Stack! show ads.

### Which is updated more often, Sudoku or Stack by Stack!?

Sudoku ships an update every 5 weeks, and Stack by Stack! every 4 days. Most recently, Sudoku was updated on August 22, 2026 and Stack by Stack! on September 27, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*